CVE-2026-97029

Flatpak: flatpak: sandboxed app can signal unsandboxed processes in the same process group

Published Sep 29, 2026 CVSS 3.1 · 5.7 Medium EPSS < 1% KEV · Not listed
Description
Flatpak's process ID namespace separation does not prevent a sandboxed app's kill(0, signal) or killpg(0, signal) calls from reaching processes outside the sandbox that share the same process group. A malicious or compromised Flatpak app can use this to cause denial of service by terminating processes outside its sandbox, such as the desktop shell.

Remediation

Vendor Workaround

Run Flatpak apps in a new session (setsid flatpak run ... or setsid() in the parent) or a new process group (setpgid (0, 0) in the parent), or avoid running untrusted Flatpak apps.

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-6524-1 flatpak security update
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Redhat rhel Els
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:rhel_els:7
Vendors & Products Redhat rhel Els
Type Values Removed Values Added
First Time appeared Flatpak
Flatpak flatpak
Vendors & Products Flatpak
Flatpak flatpak
Type Values Removed Values Added
Description Flatpak's process ID namespace separation does not prevent a sandboxed app's kill(0, signal) or killpg(0, signal) calls from reaching processes outside the sandbox that share the same process group. A malicious or compromised Flatpak app can use this to cause denial of service by terminating processes outside its sandbox, such as the desktop shell.
Title Flatpak: flatpak: sandboxed app can signal unsandboxed processes in the same process group
First Time appeared Redhat
Redhat enterprise Linux
Weaknesses CWE-653
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
References
Metrics cvssV3_1

{'score': 5.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 6, 2026, 2:18 AM
Reserved
Sep 23, 2026, 9:15 PM
Status
Awaiting Analysis
Published
Sep 29, 2026, 4:18 AM
Modified
Nov 6, 2026, 3:16 AM
Severity
Moderate
Public date
Sep 28, 2026, 1:30 PM